Process of smelting zinc-iron ore



UNITED STATES PATENT OFFICE."

JOSEPH O. KENT, OF COOPER IRON WORKS, NEW JERSEY.

PROCESS OF SMELTING ZINC-IRON ORE.

Specification forming part of Letters Patent No. 16,594, dated February 10, 1657.

To all whom it may concern:

Be it known that I, JosEPH O. KENT, of Cooper Iron Works, in the county of Warren and State of New Jersey, have invented a new and improved process for smelting in ordinary blast-furnaces Franklinite and other ores containing the oxides of iron and zinc, by which process I produce cast-iron and oxide of zinc, of which the following is a specification.

In order to make my process understood, I must premise that the difficult y heretofore encountered in working iron ores containing oxide of zinc in blast-furnaces has been the gradual clogging up and cooling of the furnace. The oxide of zinc in the orcs is volatilized in the blast-furnace a short distance above the region of the tuyeres. The sudden conversion of a quantity of the solid ore into vapor renders latent a considerable portion of the heat necessary for the successful working of the furnace. At first this evil is not serious, because the equilibrium is not destroyed; but the oxide, traversing the height of the furnaces, condenses partially on the cool layers of stock encountered in its upward progress. These again descend with their coating ot'zinc in addition to the oxide contained in the ore itself, and cause increased vaporization and ing Franklinite ore in low furnaces and con-' sunning heavy charges of coal in order to preserve the requisite temperaturebut thus far these methods, though entailing great expense, have not been successful.

Bymy process the difficulties are so far overcome that I work iron ores containing zinc successfully in an ordinary blast-furnace and without any additional consumption of minerals, and combustible above the usual requirements of blast-furnaces for the production of cast-iron.

charging the ordinary ores.

To enable those skilled in furnace operations to understand and use my invention, I will proceed to describe its details.

In any ordinary blast furnace I charge Franklinite or other iron ores containing oxide of zinc with the usual quantity of anthracite coal and fluxing material. I continue the charging until the furnace begins to show' signs of cooling in the region of the tuyeres. Ithcn discontinue the use of zinc ores and charge with any of the ordinary ores-as magnetic oxide, sesquioxide, hydrated peroxidebut preferably with ores having a silicious gangue. I continue charging these ores with the usual amount of combustible and fiuxing material until the equilibrium of heat is re stored and the furnace scoured. I then resume the charging of zinc ores, and alternate as before. I receive the oxide of zinc in the hot-blast ovens and under the boilers, using one set of boilers and hot-blast oven when charging the zinc ores and a second set when When using the latter ores I clean the zinc oxide from the boilers and hot-blast ovens which have re ceived it and collect it in bags or boxes.

In this process I use the gas from the furnace in the usual way for heating the boilers and blast, obtainingthe requisite heat by keeping the space under the boilers and in the hotblast oven unobstructed and clean.

By this method of working and alternating the ores I have kept a. furnace in operation for more than one year, and it is still in good running order. I usually run on zine ores for four or five consecutive days, and then change to ordinary ores, charging them for three or four days; but these periods will vary with circumstances,depending on the size of the furnace, quality of ores, and other matters which experience will suggest to every ironmaster.

What I claim as my invention,and desire to secure by Letters Patent, is

The peculiar process of alternating in the blast-furnace the Franklinite and other ores of iron and zinc with ordinary ores of iron for the production of cast-iron and oxide of zinc, by which process I maintain the equilibrium of heat and keep the furnace in successful operation, as herein described.

' JOSEPH O. KENT.

Witnesses:

H. A. TAPPE, L. SOM1vrEssoN. 

